Refrigerating apparatus



y 1940- R. M. SMITH 2,199,762

REFRIGERATING APPARATUS 4 Sheets-Sheet 1 Filed Jan. 30, 1937 5 5 ATTORNEYS.

' May 7, 1940. R. M. SMITH REFRIGERATING APPARATUS Filed Jan. so, 193'! 4 Sheets-Sheet 2 INVENTOR.

WMWYQIAV Ms ATTORNEYS.

y 7,1940. R. M. SMITH 2,199,762

REFRIGERATING APPARATUS Filed Jan. 30 19s? 4 Sheets-Sheet 3 INVENTQR;

, mr f 4/5 ATTORNEYS.

May 7, 1940. R. M. SMITH REFRIGERATING APPARATUS Filed Jan. 30, 1937 4 Sheets-Sheet 4 INVENTOR.

' WMJW Patented May 7, 1940 UNITED STATES aararomrnvo APPARATUS Rolf M. Smith, Cincinnati, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application January 30, 1937, Serial No. 123,258

4 Claims.

This invention relates to refrigerating apparatus and more particularly'to a novel motor-compressor unit of the hermetically sealed type for use in a refrigeration system.

I It is an object of this invention to provide a motor-compressor unit in which there is no solid metal-to-metal contact between the supporting structure and the housing for the compressor.

Another object is to provide an improved arrangement for providing lubrication for the wearing surfaces. I

Another object of this invention is to provide a simplified mounting for the rotating elements.

It is also an object to provide a mechanism of a character described which is simple, reliable in operation, durable, and at the same time inexpensive.

Still another object of this invention is to provide means for thoroughly separating the mixture of lubricant and refrigerant which is delivered from the outlet of the compressor.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accom- 25 panying drawings, wherein a preferred form of the present invention is clearly shown.'

In the drawings:

Fig. l is a vertical cross-sectional view of a motor-compressor unit constructed in accordance with this invention; 5

Fig; 2 is a vertical cross-sectional view of a modified form of motor-compressor unit embodying features of'the present invention;

Fig. 3 is a fragmentary sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a view similarto Fig. 3 with the rotor in a different position;

Fig. 5 is a view similar to Fig. 3 but showing a modified construction;

Fig. 6 is a view similar to Fig. 3 but showing a 40 still further modified arrangement:

Fig. 7 is a fragmentary cross-sectional view taken on line 'l'| of Fig. 2;

Fig. 8 is a fragmentary cross-sectional view 45 taken on line 8-8 of Fig. 2;

Fig. 9 is a vertical cross-sectional view of a still further modified motor-compressor unit embodying features of this invention;

Fig. 10 is a fragmentary cross-sectional view 50 taken on line lO-lll of Fig. 9; and

Fig. 11 is a vertical cross-sectional view of still another modification.

Referring now to Fig. 1, there is shown a motor-compressor unit having an outlet 2l from 55 which compressed refrigerant is adapted to be delivered to the usual condenser unit (not shown). Conduit 22 delivers expanded refrigerant to the inlet 23. The, motor-compressor unit comprises a housing 24 having an open bottom which is closed by a base member 25 which in turn is v welded to the housing 24 at 26- to form a hermetically sealed chamber 21. Within the chamber 21 in the upper portion thereof, there is mounted an electric motor comprising a'stator 28 and a rotor 29. A stationary shaft 30 is located centrally of the housing 24 and mounted rigidly as by welding in the base 25. A socket member 3| secured to the top of the housing 24 positions the upper end of the shaft 30. A hollow compressor drive shaft 32 is journaled on the 1 shaft 30, carrying at its upper portion the rotor 23 while at the lower end there is provided an eccentric journal 33. The vertical bearing load .is carried on the thrust surface 35 formed on the base 25 of the casing. The bottom surface of the compressor bears against this thrust surface.

The'compressor comprises the cylindrical casing member 36 which is provided with lower end plates 31, 38 and 39,an uppervalve cover plate 40, and a retainer plate 40a. Bolts 4| hold members 36 through 40 in assembled relationship.v

The lower end of the shaft 30 is provided with a passage 43 through which low pressure refrigerant entering through the conduit 22 may pass on its way to the inlet port 42 of the compressor. 30 The compressor is provided with the usual type of divider block (not shown) which separates the inlet port from the outlet port. The usual type of flap valve 44 is placed over the outlet port for the compressor. The compressed refrigerant, 35 leaving the outlet port, is forced to pass between the cap member 45 and oil throwing means 46. The outside diameter of the means 46 is' approximately equal to the-inside diameter of the upper opening in cap with the result that the lubri- 40 cant and refrigerant leaving the compressor can not escape very readily without being subjected to the centrifugal forces resulting from the rotation of member 46 which together with the flange 46a tends to throw the lubricant outwardly. 45 The above action tends to separate the lubricant from the refrigerant. Further oil separation will take place as the compressed refrigerant passes between the motor rotor and the motor stator on its way to the outlet 2| for the compressed 50 refrigerant. A sufflcient supply of lubricant will be maintained on the upper end of the compressor so that oil will flow downwardly onto the eccentric portion 33 and will work its way onto the impeller-52. The usual type of feed screw arin the usual manner.

rangement 83 causes ,oil to be forced downwardly through the passage 84 to the lower shaft bearing. From this point the feed screw 58 carries the oil upwardly between the rotating member 32 and the stationary shaft 38 in the usual manner. A supply of any kind of suitable lubricant 59 is provided in the lower end of the compressor. The thrust surface 35 is provided with an oil groove 58 which supplies lubricant to the surface 85. I

It will be noted that with this arrangement the compressor housing, that is the member 38, and all parts secured thereto are floatingly mounted on the rotating part 32. In order to prevent rotation, however, a stud 56, which is threaded into the member 39, is anchored in a flexible bushing 51 carried by the member 58 which is rigidly secured to the bottom plate 25 of the motor-compressor housing. The bushing member 51 may be made ofany rubber-like material unaffected by the refrigerant and lubricant, as for example, a polymer of chloro-2-butadierie-L3.

In Fig, 2 I have shown a modified arrangement in which the bell member 88, which serves as a portion of they motor-compressor housing, carries the stator SI of the motor as well as the supporting shaft 82 which in turn carries the working loads of the compressor. It will be noted that in this arrangement there is no rigid connection between the central shaft 62 and the motor-compressor housing except through that end of the shaft which is attached to the bell member 88. As shown in Fig. 2, the upper end of the shaft 82 is rigidly held by the bell member 80. The lower end of the shaft member 62 supports the rotating parts of a motor-compressor unit including the motor rotor 84 and the compressor eccentric 85.

The general arrangement of the compressor has not been changed. The compressor is provided with the usual cylindrical housing 65a, lower end plates 88, 81 and 88 and an upper valve plate 69 together with a retaining plate I8, all of which are held together by means of bolts I2 Fig. 7 is a cross-sectional view showing the relationship of the various moving parts of the compressor. The lower end of the shaft 62 has a reduced portion 13 which is threaded. A nut member 14 cooperates with the threaded portion and holds in place the end thrust washer I5.

Expanded refrigerant is admitted to the compressor through the pipe I8 which delivers low pressure refrigerant to the compressor in the usual manner. Compressed refrigerant leaves through the usual outlet port which is provided with a flap valve I8. The compressed refrigerant leaving the compressor is caused to pass through the oil separator which is of the same general type as the oil separator shown in Fig. 1. The compressed refrigerant leaves the motorcompressor housing through the outlet 19.

A resilient bushing member 88 is secured to the stationary part of the compressor by means of a housing 82 which is anchored to the compressor by means of a bolt 82a. In order to prevent rotation of the compressor housing the "threaded stud member 83 has beenjiprovided,

which has its upper end passing through the resilient bushing 88 and its lower end threaded into a projection 84 which is rigidly secured to the lower cup-shaped member 85 which in turn is.

welded or otherwise secured to the bell member 68 at 86.

As shownin Fig. 2. a bath of lubricant 98 is provided in the lower portion of the motor-compressor housing. In order to avoid making the lubrication depend upon lubricant discharged from the compressor, I provide a groove 88 in the bottom face of the eccentric 65 which registers with the oil port 81 provided in plates 86, 81 and 68. This groove in the bottom face of the cocentric is of a peculiar shape and, as shown in Figs. 3 and 4 has one portion 88 extending substantially across the lobe of the eccentric to a spiral groove 8i on the outside of the eccentric. A branch spiral 89 extends from this first named groove on the bottom face of the eccentric to the inside of the hollow eccentric shaft. This provides for flow of lubricant directly from the lubricant collected in the bottom of the sealed unit to the bottom face of the eccentric where it is trapped and carried by the main groove 88 to the outside of the eccentric and through the branch groove 89 to the bearing surface on the inside of the eccentric. Sufiicient pressure is created in these grooves to carry the lubricant without much difiiculty to the bearing surfaces on the outside of the eccentric and also to the lower and upper bearing surfaces on the stationary shaft 62.

Fig. 5 shows a modified groove arrangement which may be used in lieu of the groove arrangement shown in Figs; 3 and 4.

Fig. 6 shows a still further modified groove arrangement which may be used to distribute oil to the various wearing surfaces.

The shaft 62 in each case is provided with a spiral groove 9| which serves to convey lubricant to the main bearing surfaces between the shaft 82 and the rotor 68;

In Fig. 8 I have shown a cross-sectional view taken on line 8-8 of Fig.2. This view, in effect, is a top view of the compressor showing more clearly the relationship between the inlet port I8, the divider block 1 la and the outlet valve 18.

In Fig. 9 I have shown a still further modification in which a main spider frame I88 is provided with a cylindrical hub I8I which serves, together with the bottom end plates I82, I83

and I 84 and the upper valve plate I85 and retainer plate I88, to form a compression chamber. The various end plates I82 through I86 serve to support the main shaft I81, which is provided with an eccentric portion I88, oil-throwing portions I89 and H8, and which carries on its upper end the motor rotor III. The two cupshaped members I I2 and H3, which are welded or otherwise held together at H4, hermetically inclose the motor and compressor as a unit. It will be noted that the motor stator I I5 is carried directly by the member I88. The upper casing member II2 is provided with an end thrust hearing 6 which prevents the main shaft I 8'! from being displaced endwise too far;

As shown in Fig. 10, a divider block II! has been placed directly adjacent one of the spider arms II8. -With this arrangement the compressor cylinder, or in other words the hub of this spider has not been weakened to any appreciable extent by the groove II9 which accommodates the divider block I". The usual form of impeller I28 has been provided.

A supply of oil I2I has been'provided in the lower 'end of the motor-compressor casing. Oil for the bearingsurfaces is fed up through the oil port I28 and is carried by the grooves I24 on the eccentric to the upper bearing surfaces of the shaft I81. This compressor also is provided with the same general type of oil separating means as shown in the previously described modcribed in detail.

' compressor.

ifications and for that reason will not be de- The upper end of the hub IOI' carries an oil-retaining ring I which provides an oil seal between the members IOI, I05 and I06.

It is apparent that in this modification an unfailing supply of lubricant will be available at all times to lubricate the wearing parts and also to provide a lubricant seal for the compression chamber.

In Fig. 11 I have shown a still further modi-- fied arrangement embodying features of my in-' vention. The main support is a spider member I which is of the same general shape as that shown in the modification shown in Fig. 9 except that it has been modified so as to provide a compressor having the discharge port on the underside of the compressor in lieu of the top side of the compressor as in the modification shown in Fig. 9. In this modification the motor stator I3I is carried by the spider I30 and the hub portion I32 of the spider has secured thereto the upper end plates I33, I34 and I35 and the lower end plates I36, I31 and I30. Members I32 through I38 forma compression chamber.

The main drive shaft I40 is provided with an eccentric portion I4I which drives the impeller- I42 in the usual and well-known manner. Low pressure refrigerant is fed to the compressor through the conduit I43 and is discharged from the compressor through the outlet port I44.

Inasmuch as the refrigerant circulating through the system carries with it a certain amount of oil, the lubricant and refrigerant which is discharged through the port I44 is confined by means of the oil pan I45 which is secured to the lower end of the compressor by means of the bolts I48. The shaft I40 is provided with a central bore I4I through which the compressed refrigerant is forced to travel on its way to the outlet I60.v The refrigerant passing through the bore I4I carries with it a certain amount of lubricant. This lubricant together with the refrigerant is discharged through the elbow member I48 which is fitted within the upper end of the bore I4'I. upper end of the shaft I40 is an oil separating and retaining member I49 which receives the oil and refrigerant discharged through the elbow I48. It will be noted that the member I49 is provided with a first pocket I50 and a second pocket I5I. Due to the centrifugal force a certain amount of the oil will separate out from the refrigerant, a portion of which oil will collect in the pocket I50 and the remainder of which will travel along the frustro-conical surface I52 until it reaches the pocket I5I. When the pockets I50 and I5I have become filled excess oil will be thrown out at the upper end of the member In order to provide lubrication for the bearing surfaces I have provided an oil passage I53 in the shaft I40 which is supplied with oil from the pocket I50. This passage leads downwardly and communicates with the radial passage I54 which supplies lubricant to the pocket between the eccentric Ill and the impeller I42 of the In order to increase the bearing surface for the shaft I40 I have provided a plurality of plate members I55, I50 and I51 which are constructed so as to provide an oil pocket I58.

This oil pocket I58 is kept supplied with oil by means of a radial passage I59 which communi- Attached to the rate out of the refrigerant immediately a the compressed refrigerant reaches the discharge port I44. Additional oil. will separate out of the refrigerant as the mixture of refrigerant and oil passes through the central bore I'4'I in the shaft I40. Still further separation takes place after the oil leaves the elbow I 48 with the result the refrigerant before the refrigerant is discharged through the outlet I60. The surplus oil form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. 4

What is claimed is as follows:

1. A unit adapted to circulate a refrigerant comprising a halogen derivative of hydrocarbon and a lubricant at least one of which has a deteriorating effect. on rubber, said unit having a cylinder and a piston movably mounted within said cylinder, means for moving said piston within said cylinder, a stationary shaft upon which said means is mounted, means for mounting said shaft within said unit, and a yieldable means for preventing relative rotation between said cylinder and said shaft, said yieldable means comprising a portion formed of a polymer of ch1'oro-2- butadiene-l,3.

2. A sealed unit adapted to circulate a refrigerant and a lubricant at least one of which has a deteriorating efiect on rubber, said unit having a cylinder therein and a piston movably mounted within the cylinder, a motor within said sealed unit, means drivingly connected with said motor and said piston for moving said piston within the cylinder, a vertically disposed stationary shaft upon which said means is mounted, resilient means for preventing relative rotation between said cylinder and said shaft, said resilient means comprising a portion formed of rubber-like material unaffected by the refrigerant and lubricant.

3. In a motor-compressor unit, a hermetically sealed housing partially fllled with a lubricant, compressor mechanism partially submerged by said lubricant, said compressor mechanism comprising a casing, a stationary central shaft, an eccentric member. rotatably mounted on said shaft, said casing having an aperture for admitting lubricant to an end surface of said eccentric member, said'end surface having a substantially V-shaped groove one arm of which leads to the outside surface of said eccentric and another arm of which leads to the inside surface of said eccentric.

4. In a rotary compressor, a compressor housing, an impeller within said housing, a drive shaft having an eccentric portion within said housing in driving engagement with said impeller, said housing having a lubricant passage leading to one end surface of said eccentric, said end surface being provided with a bifurcated groove having one branch leading towards the'center of rotation and another branch leading to the out- I side surface of said eccentric. cates with the main oil passage I53. With this arrangementacertainamount ofoilwillsepa-- ROIFMSMITH.

that the oil becomes sufiiciently separated from 

